Genetic characterization of the Drosophila jaguar322 mutant reveals that complete myosin VI loss of function is not lethal.

Myosin VI is an actin-based motor that has been implicated in many cellular processes. Studies in vertebrates have demonstrated that animals lacking this ubiquitously expressed myosin are viable. However in Drosophila, myosin VI loss of function has been thought to be lethal. We show here that complete loss of myosin VI is not lethal in flies and that the previously reported lethality of the null mutation (jar322) is most likely due to deletion of a neighboring gene. Maternally provided myosin VI does not account for the survival of myosin VI null animals. Mutant animals are recovered at a lower than expected Mendelian frequency, suggesting that myosin VI participates in processes which contribute to normal development, but its participation is not essential.